This invention relates to devices for use with bags of food, pet food, potting soil, and other bulk items. More particularly, this invention relates to devices used to close and open these types of bags.
A previous invention, U.S. Pat. No. 6,105,217, xe2x80x9cBag Clampxe2x80x9d, was co-authored by this inventor, and this patent application is a set of improvements to that invention.
As covered in the cited patent application, modern polymer plastic bags are useful containers for bulk foods, bulk pet foods, and other loose, granular or small-sized items. The bags have the drawback that they are difficult to close properly once opened. They usually have smooth or slick surfaces which are difficult to grab with closure devices.
Polymer bags such as those under consideration here are often opened with the intention of closing and then re-opening then at a future time. Secure closure of the bag, to preserve product freshness for example, is necessary as is easy re-opening. Therefore, a bag closure device of this type should securely close the opened bag and be convenient to use to re-open. The previous invention by this inventor accomplished these goals by use of a strong spring to keep the device closed and by distributing the gripping force along the length of the device rather than concentrating it in the center of the device.
There are competing devices in use that also close polymer bags, but they largely fail to close and keep closed heavier bags. The competing devices tend to slip off of the bag surface easily and are much less useful.
In the cited patent, this inventor developed a device that could be made in a variety of sizes while retaining the generic characteristics of the invention. The small versions could be used for potato chip bags, popcorn bags, and the like, while the largest size would be capable of closing and re-opening larger bags of potting soil or pet food. The large device was strong enough to prevent spillage of product if a bag was knocked over, for example.
Opening polymer bags is also a problem, because they are usually tightly sealed to prevent product degradation while on store shelves. A method of quickly and predictably opening such bags is also desirable. Providing such a method prevents bag tearing, destruction of the bag, and spillage of bag contents while making bag closing and re-opening more straight-forward. The cited invention possessed features to aid consumers in opening polymer bags in an easy and safe manner, long with the above-described closure, clamping and reopening features.
The present invention is a set of improvements to the cited invention co-authored by this inventor. The additional features are non-obvious and confer additional, valuable, and useful capabilities to the cited invention.
In common with the cited invention, there is a clamp for closing and holding closed a polymer bag, consisting of a pair of opposed clamp members, where these clamp members can be moved from a closed to an open position by pressing on them with the hand. A hinge connects the two members and holds them closed with the aid of a spring. There is a sharp blade on the inside of the xe2x80x9ctopxe2x80x9d member held underneath a blade guard and opposite a split anvil. The blade does not extend past the guard in its rest position. The blade guard rests movably on one end on a fixed rest and is fixedly attached on the other. The blade guard has a slit down its length that permits the blade to emerge when a springboard button that it is connected to is pressed by the user gripping the bag clamp.
By pressing the button with a thumb while gripping the device, the blade is pushed through the slot in the guard and can then engage a polymer bag and cut it. When the button is not being pressed, the blade is retracted behind the guard for safety reasons.
The blade itself is improved over the previous invention, possessing increased sharpness and an improved cutting angle for maximum cutting efficiency. This is possible because of the added safety for users conferred by the blade guard.
The anvil of the previous invention is now a split anvil, with two parallel sides between which the blade fits and is guided. These changes to the previous invention are non-obvious safety improvements. The split anvil also holds bag material up to allow the blade to more easily penetrate the bag. When the blade is pressed through the guard, the guard itself is held against the split anvil, and the blade never contacts the anvil.
There are a set of ribs on the inside of each clamp member, configured so that the rib ridges on opposite sides meet when the clamp is closed. These ribs are designed to aid holding the bag when the clamp is closed. The ribs have an additional effect of stretching the bag material so that the blade can be more effective in cutting. The ribs also distribute the gripping force away from the hinge spring location.
The clip mouth ends also meet (the xe2x80x9clipsxe2x80x9d), and allow the bag to be drawn through the clip during the cutting process. There is in this improved invention an additional xe2x80x9ctoothxe2x80x9d in the middle of the bag xe2x80x9clipsxe2x80x9d. The improved spring is now strong enough to hold larger bags than before.